Pitman end



sept. l e, 1927. 1,641,533

B. H. DAVIS PITMANEND Filed March v1a, 1925 'l b 777%# www ,gm/6.

Li .fi

Patented Sept. 6, 1927.

UNITED STATES PATENT i oFElcE.

PITMAN END.

Application led March 18, 1925. Serial No. 16,327.

ing hole rapidly wears large and there is noreffective way of reducing the size of the hole, or in other wordsl of tightening. the bearing.

An object of the invention is to provide an improved pitman end, preferably made.

of meta-l wherein an adjustable bearing is adapted to co-operate with the wrist pin of the band wheel crank. l

A Afurther object is to incorporatev in a pitman end of the type described, demount` able parts so that when the bearing parts or other parts which wear may be readily replaced. f

A further object is to provide means .for rapidly coupling'the pitman end bearing with a wrist pin or quickly disengaging the bearingl if desired. y

Other objects and advantages will be made manifest in the following specification of an embodiment of the invention illustrated in the accompanying drawings, in which:

Figure 1v is a vertical side view partly in section of the pitman end.

Figure 2 is a vertical end'view of the pitman end.

Figure 3 is a fragmentary sectional view of the pitman end taken on the line 3-3 of Figure 1.

Figure 4 is a fragmentary side view of a standard oil rig having the improved pitinan end incorporated therewith.

The details of construction are as follows:

Referring to Figure 4, a walking beam 2 swinging upon a Sampson post 3 is linked with a band wheel 4 by a pitman rod 5 which engages a wrist pin 6 at the end of a band wheel crank 7.

The lower end of the pitman is provided with a bearing 8 which is formed in two halves, a lower half 9 and an upper half 10. The bearing is adapted to be retained.k

in a. box 11 provided in a counterbalance l2 which be a suitable casting and is prefsrehiy rounded at its lower end. 'the the pitinan end which co-operates with with a block 15 which extends crosswise of the counterbalance as indicated in Figure 1 and has an inclined upper face 1G. Adapted to slidably engage the upper face 16 of the block 15 is a wedge member 17 whose lower face is inclined to co-operate with the inclined face 16, and whose upper face 18 is substantially horizontal. A guide block l19 having a horizontal lower face adapted to engage the upper face of the Awedge member 17 has a roughly U shaped outline and is adapted to seat upon thelower end 20 of the upper part of the pitman, which may be of` wood oi any suitable material.

The guide block 19, the wedge member 17, and the block 15 are all dove-tailed longitudinally of their extension and ciosswise of the countei'balance, so that they may be slidably related one to the other and for other purposes hereinafter described.

A `metal band 21extends Ifrom the upper end ofthe pitman 5 down what has been referred toas a vertical end of a pitman, is looped around the lower end ofthe counterbalance 12 and passes upwardly to the upper end of the. pitman. This band 21 is intended to firmly secure the counterbalance and the bearing mechanism in secure relationship with the upper' part of the pitinan. Bolts 22 lextend through the metal band and through the guide block 19 rigidly maintaining the guide block at' the lower end of the, upper part 2O of the pitman.

y rlhewedge member 17 is provided with a longitudinal and horizontally threaded opening 25 and a recess 2,6 at the larger end of the wedge member andV (zo-extensive with the threaded opening 25. A jack screw 27 is adapted to operate in the threaded opening 25 and is provided with a crank 28 which may be removed when the pitiiian is operating. The jack screw extends through an opening in the metal band 21 and is provided immediately adjacent the inner side of the band with an annular shoulder 29 adapted to act as a thrust bearing, and upon the outer side of the metal band a ratchet wheel '50 which is adapted to act as a second thrust bearing for the jack screw and is fur-A adapted to be engaged a dog- B1 ion l which is pivoted upon the metal band immediately above the ratchet wheel.

The lower half 9 oli' the bearing is adapted tov seat loosely in the box 11 until pressure is brought to bear upon the bearing and the height otl the bearing may be adjusted by placing shims between the bottom ot the boX and the bottom of the bearing block.

In the operation of the invention the upper half 10 of the bearing should be separated from the lower half 9 by turning the crank 28 iii a left hand direction, which will cause the wedge member 17 to be diawn outwardly,iinasmuch as the annular shoulder 29 and ratchet wheel 30 provide thrust bearn ings restricting the shalt from longitudinal movement, and the recess 26 will accommodate the annular shoulder 29. Inasmuch as the guide block 19 is rigid with the pitman and the wedge member 17 is slidably dovetailed with the guide member and also with the inclined face of the block 15, the outward movement of the wedge member 17 will cause the block 15 to be raised and consequently the upper half 10 of the bearing will be raised considerably above its normalV position. The bearing may then be drawn into approximate engagement with the wrist pin (3 on the band wheel crank and a turning of the crank 28 in a right hand direction will cause the wedge member 17 to slide inwardly co-acting with the block 19 to press the block 15 downwardly so that the bearing may be tightened as desired. The dog 31 dragging on the ratchet wheel 30 will prevent retraction ofl the wedge member so that the bearing may be irmly retained at the adjustment desired. The crank 28 should then be removed while the pitman operates.

It will be noted that on account of the dove-tail connection oi' the wedge member i7 to the block 15 and the guide block 19 that when this wedge member is drawn outwardly the bearing block 15 may be positively drawn away from the wiist pin and may be held in such position by means of the ratchet and pawl. Y

`Various changes may be made without departing from the spirit of the invention as claimed. What is claimed is:

1. In a pitman rod, a pitman end having a split bearing, one half of the bearing being stationary with respect to the pitman rod and the other halt being movable relatively thereto, a guide block mounted uponV i' the pitman rod, a wedge disposed between the movable halt of the bearing and the guide block, said wedge having a dove-tailed connection with the guide block and the movable half of the bearing, whereby it may slide relatively thereto but can not be separated theiefroim'a screw threaded into the wedge and held againsteiidwise movement relatively to the. pitma-n rod, a ratchet wheel rigidly mounted upon the screw, and a pawl mounted upon the pitman rod eiigageable upon the ratchet wheel, whereby the screw may be rotated in either direction to cause the wedge to slide in either direction and thus move the movable half ot' the bearing in either direction.

2. In a pitinan rod, a metal band encircling the lower' end of the pitman rod, a box mounted within said band and tastened thereb to the aitman rod a bearing iii said l a n boX, said bearing comprisingv a lower halt adapted to tit 1n the boX, an upper halt adapted to cooperate with the lower halt and having an inclined face, a guide block dif*- posed above said box, and a wedge member cio adapted to slidiiigly engage the guide blocl: -f

and the inclined face of the upper halt of the bea-ring, the wedge member, the upper halt ot the bearing and the guide block having a dove-tailed connection,a screw thread ed into t-he wedge member having one end rotatably mounted in said band, said screw being held against endwise movement through the, band, a ratchet' wheel rigidly mounted upon the screw against the outer side of the band, and a pawl mounted upon the band engageable upon the ratchet wheel, said screw having a non-circular end whereby a crank or the likeiiiay be detachably applied thereto to rotate the screw in either direction and cause the movable. half of the bearing to move toward or away from the stationary liali of the bearing.

`In testimony wliereoic I have signed my name to this specification.

BERNARD H. DAVIS. 

